Hypodermic syringe.



J. H. WBDI G. HYPODERMIG SYRINGE.

APPLICATION FILED SEPT. 28, 1912.

1,100,799. Patented June 23, 1914,

WITNESSES: INVENTOR m. 1 WW. jfl/m WW/My,

ATTORNEY.

llll) till ' UNITED STATES PATENT OFFICE.

Specification of Letters Patent.

Patented June 23, 1914.

Application filed September 28, 1912. Seria No- 722,888.

To all whom it may concern:

Be it known that I, JOHN HARRISON llams, a citizen of the United States, residing at Granite City, in the county of Madison and State of Illinois, have invented certain new and useful Improvements in Hypodermic Syringes, of which the following is a specification.

This invention relates to certain new and and useful improvements in hypodermic syringes.

in a prior a plication filed by me May 25, W12, Serial 0. 699772, I have described and claimed a two-chamberedsyringe with a ug seal dislodged by a stylet.

present application relates to other means for establishing communication between two chambers, for securinggreater compactness, and to other peculiarlties hereinafter described and claimed.

in the accompanying drawing on which hits reference letters indicate corresponding parWFigure 1 represents a longitudinal sectional "View of a syringe embodying my improvements, and in normal position of parts, Fig. 2, a similar view with the chamhers cunicating and the piston head and piston rod engaged ready to force out the charge-and Fig. 3, a similar view with the parts in position when the charge is expolled. I

The letter A designates a cylindrical barrel lormingthe body of a syringe, having a forward endv B, preferably tapered, and having an axial chamber C of cylindrical or other form at the outer end of which is mounted a suitable hypodermic needlel) by a lead dish E or other means that holds the inner end of the needle and forms the varisble ,outer Wall of said chamberC. The needle is supported beyond said chamber by a filling of sealing wax or other suitable material F, that embraces the burred end of the needle. By adjusting the disk .E farther forward or backward, a larger or smaller chamber C is respectively formed between the dish and a seal G that closes said chamber (7 from the main chamber H in the barrel. This seal G is preferably formed by the tapered recessed end (suitably packed by asbestos or otherwise) of a piston rod I, that as a correspondingly tapered portion at the walls of the axis chamber C and limits the extent of this chamber C at its inner end when in the position shown in Fig. l A drug or other medicament is located the piston rod drawn back 1:

in said chamber C, and is thus sealed from a hydro-alcoholic, or other solvent, which is located in the chamber H, that has a piston head J slidingly mounted in the rear of said barrel to constitute the rear wall of the chamber H. Asbestos or other suitable packing .K', fills in a 'recess L in said head and bears against the barrel so as to make a snug sliding fit. The rod I passes through an axial opening in this piston head and is suitably plucked by-a ring of asbestos Within a recess so as to make a tight sliding fit of the rod through, the piston-head. A button N on the outer end of the rod, facilitates drawing back the rod through the piston head to the position'shown in Fig."2;" The piston head does not move back when the rod is drawn back, but it is arranged to connect up the rod and piston head so that both will move forward under pressure on the rod, to force out the charge. This connection is effected by any suitable means, such as :1 lug O ncarthe forward end of the rod, that enters a recess P in the piston head when the rod has been drawn out to its full length, and engages a notch Q by taming the rod.

In filling this syringe for sale, the size of the chamber is determined according to the roper quantity of the drug to be used. he needle with its lead disk E, is adjusted further .out of or into .the forward end B, to make the chamber (l larger or smaller respectively, and the burred end of the needle is secured. The drug or medi cament is deposited in the chamber C, and the tapered end of the rod with its packing, seals up the-chamber. The solvent liquid is poured into the barrel around the rod.

and the piston head is slipped over the rod to the position in the barrel that will provide a chamber H of the size tocontain the suitable quantity of solution for the clm rge,-the excess passing out through the rent which is then stopped by parafiin filling behind the Npiston head as shown at 11. The button is fastened to the rod, the stylet d is inserted in the needle, and the casing 6 is slipped over theta red end B. The drug and its solvent are ept separate until the solution is required for use, and the strepgeth and uniformity are maintained.

n the syringe is to be used, the needle cap is removed, the stylet ulled out, and

ugh the piston head. This withdrawal of the r d opens the seal G at the end of the rod, thus establishing communication between the drug chamber and the solvent chamber H, so' that the solvent. has free access to the drug. Furthermore, the withdrawal of the rod from the solvent chamber-causes a corresponding inrush of air through the needle that acts on the drug in the chamber C to force it, inward into the chamber H and distributeit in the solvent whereby the outlet of the needle is cleared'and the drug is caused quickly to dissolve in the solvent Thus the drug is kept separate from the olvent until the charge is required, and the solution made with certainty and speed. A partialturn of the Withdravvnpiston rod in the construction shown engages it with the piston head; The needle is held upward and pressure on the thumb piece causes the rodand piston head to move outward together V lVhen all the air is ex elled, as shown by a'drop or two of the so ution appearingat the outlet the needle, the needle is, inserted intoth'esubject and the charge isexpelled by continued pressure on the thumb iece bringing the arts into the positien s own in Fig. 3. ractiically all of the charge is expelled, asgonly the small quantity remains that is contained in the needle itself, the drug chamber and recess P in the piston head.

The preferred material for the main arts of this syringe' is glass on account of its aseptic qualities, freedom from corrosion and cheapness The finger lugsat the rear of the body. aid the fingers and thumb in operating the syringe. 'ihe' taper of the outer jend of the rod acts to compress the .packingMwhen the piston head is slipped over the rod and inserted in the barrel. i lay especial stress on this function of the seal rod of increasing the size of the solvent chamber when it; is'dravvn outward, whereby-the drugchainber isthe more readily emptied of its contained drug or medicament' Theses-ling position of the rod locates all but the thumb piece and rear end within the body securing compactness and safety from breaks, c.

Having thus 'fnl y described my inven oifone chamber, a piston head forming the rear wall of said chamber and adapted to be engaged by said rod substantially as and for the purpose described.

3. A hypodermic syringe comprising a needle and a body containing a drug chamber adjacent to the needle and a solvent chamber adapted to communicate with said drug chamber, a seal rod normally sealing the drug fromihe solvent, chamber and passing through the solvent chamber to be operated outside, whereby the increased volume of the solvent chamber corresponding, to the withdrawal of the rod tends to displace the contents of the drug chamber and inject the drug into the solvent, and a piston head adapted to eject the charge through said needle.

t. A hypodermic syringe comprising a needle and a body containing a solvent chamber and an adjacent drug chamber, a piston head slidably mounted at the rear of the solvent chamber having an axial opening with a re s and a Shoulder on the inner face, and a scalrod passing through said opening having a soul at its innercnd to Close said drug chamberfrom the solvent chambeer and a lug near the seal end adapted to enter said recess and engage said shoulder when the rod is drawn back and rotated, whereby both will move forward in unison to eject the char e.

in testimony w ercof l have afiixed my signature in presence of tw witnesses.

JUHN HARRISON 'WEDIG.

Witnesses:

WILLIAM H. MCCLELh-\N, J12, Gnn'rciinn Lace. 

